The Big Four by Agatha Christie

Hercule Piorot takes on a quartet of evil trying to get domination of the world. The leader is from China and the others are a scientist from France, a businessman from America and an actor from Britain.

There scientist has made strides with new inventions which the team plans to leverage to dominate the world. They are desperate to eliminate Hercule Piorot so that they have no hurdles in achieving what they are up to.

The book as expected about how Piorot goes about outwitting them in his own inimical way helped by Hastings.